JPS5833522A - Rear wheel driving mechanism of motor tricycle - Google Patents

Abstract

PURPOSE:To enable to realize the large minimum under clearance of the motor tricycle by a structure wherein a final gear is made small by employing multi- step reduction between the output shaft of the engine-transmission assembly and the rear wheel shaft of the motor tricycle through a gear transmission means. CONSTITUTION:The rotation of the output shaft 30 of the engine-transmission asembly is lowered enough through an intermediate larger gear 36 and further through an intermediate smaller gear 38 and a rear wheel side gear 40. Because the reduction is made through the intermediate gears 36 and 38, the diameter of the rear wheel shaft gear 40 is made smaller as compared with the diameter of a sprocket wheel used in conventional chain-drive reduction system. As a result, a compact gear case 44 is realized and the larger minimum under clearance can be possible.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rear wheel drive mechanism for a tricycle, and particularly to a rear wheel drive mechanism for a tricycle having one front wheel and two rear wheels.

Since tricycles are used off-road in areas such as farms and wetlands, their running performance is affected by road clearance (the gap between the road surface and the bottom of the vehicle body).

That is, in a tricycle, the larger the road clearance described above is advantageous when traveling on uneven terrain. On the other hand, the conventional three-wheeled J1i does not use a chain drive system, but due to the usage conditions of automatic three-wheeled vehicles, a greater drive torque is required at low speeds than at high speeds, and deceleration by the engine transmission is required. It is necessary to increase the reduction ratio in the subsequent secondary reduction, that is, the chain drive part, and as a result, the diameter of the rear wheel shaft sprocket becomes large. In this way, in a chain drive type tricycle, the sprocket on the rear wheel axle has a large diameter. becomes smaller.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a non-automatic tricycle that can have a large road clearance.

The present invention provides multi-stage deceleration between the output shaft of the engine transmission and the rear wheel shaft through the gear transmission means, so the final gear attached to the rear wheel shaft can be appropriately reduced in size by distributing the gear ratio. The result depends on whether the road clearance of the tricycle is increased.

Preferred embodiments of the rear wheel drive mechanism for a tricycle according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a plan view of a tricycle to which an embodiment of the present invention is applied, and FIG. 2 is a partially sectional side view thereof.

In the figure, IO is a steering wheel, 12 steering head pipes, 14 a front fork pivoted to the steering head pipe 12, and 16 a front fork 14.
The front wheel is supported by Furthermore, a front cover 18 extends toward the rear of the vehicle from behind the steering head pipe 12, and covers the top and side surfaces of a fuel tank (not shown).

Two rear wheels 20,20 are secured to both ends of a rear wheel axle 22 shown in FIG. A rear cover 241't continues from the front cover 18, covering the rear wheels 20. 28 is stuck.

Next, a transmission mechanism between the engine 26 and the rear wheel shaft 22 will be explained with reference to FIG. 2. The rotational force from the engine 26 is 1
The transmission is then decelerated and transmitted to the output shaft 30 of the engine mission.
A gear 32 is fixed to the gear 0. Furthermore, this gear 32
It meshes with the intermediate large gear 36 fixed to the V'i intermediate 1 pongee 34.

Further, an intermediate gear 38 is fixed to the intermediate shaft 34, and this intermediate gear 38 meshes with a gear 40 fixed to the rear wheel shaft 22. Note that the rear wheel side gear 40 is divided into a radially outer and inner portion via a rubber damper 42, and the rubber damper 42 is designed to absorb impact force when a sudden load is transmitted.

Output shaft side gear 32, intermediate gear 36.38. Rear wheel side gear 4
0 is housed in a gear case 44 with a closed structure. The gear case 44 is connected to the front half 48 and the rear half 5 via the base 46.
The front half 48 is formed integrally with the crankcase 52 of the engine 26, and the rear half 50 is integrally formed with a heavy frame (not shown).

In FIG. 1, reference numerals 54 and 54 indicate a pair of footrests, 56 indicates a brake pedal, 58 indicates a shift pedal for speed change, and 60 indicates a knob for a starting/helping rope.

In the embodiment according to the present invention configured as described above, the rotational force of the output shaft 300 of the engine transmission of the engine 26 is reduced through the gear 32 and the intermediate large gear 36, and is further reduced through the intermediate gear 38 and the rear wheel side gear 40. It is possible to achieve a sufficient reduction ratio. In this way, in the embodiment according to the present invention, even though a sufficient reduction ratio can be achieved, the reduction is performed via the intermediate gears 36 and 38, so the rear wheel side gear 40 is replaced by the conventional chain drive system. The gear case 44 can be configured to have a smaller diameter than the sprocket shown in FIG. In addition, conventional chain drive type tricycles require a chain case for off-road driving, but in order to adjust the chain tension, it is necessary to provide an elongated hole for the rear wheel shaft penetration on the side of the chain case. Because of this length, there was a risk that water and mud could get into the chain case while the chain was running. However, in the embodiment described above, since a gear transmission system is used, there is no need to adjust the chain tension, and since the gear case 44 can be constructed in a completely sealed manner, maintenance of the drive mechanism is facilitated.

As explained above, according to the rear wheel drive mechanism of the tricycle according to the present invention, the output of the engine transmission - the shaft side gear and the rear wheel shaft side gear are decelerated in multiple stages through the gear transmission means to transmit rotational force. Because of this, the gear on the rear wheel shaft side can be constructed with a relatively small diameter, which allows for a large road clearance, which is advantageous for tricycles used off-road.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a tricycle to which an embodiment of the present invention is applied, and FIG. 2 is a partially sectional side view of a tricycle to which an embodiment of the present invention is also applied. 16... Front wheel 20... Rear wheel 22... Rear wheel shaft 26... Engine 30... Engine transmission output shaft 32... Engine transmission output shaft side gear 34... Intermediate shaft 36. 38... Intermediate gear 40... Rear wheel shaft 11111 Gear 44... Gear case agent Tatsuyuki Unuma (and 2 others)

Claims (1)

[Claims] The engine transmission is transmitted through a gear transmission means consisting of a gear fixed to the output shaft of the engine, an intermediate gear meshing with the gear, and a gear fixed to the rear wheel shaft meshing the intermediate gear. A rear wheel drive mechanism for tricycles that decelerates the rotation of the output shaft and transmits it to the rear axle. (2) Claims in which a gear fixed to the output shaft of an engine transmission, an intermediate gear that meshes with the gear, and a gear fixed to the rear wheel shaft and meshes with the intermediate gear are housed in a sealed gear case. The rear wheel drive mechanism of the tricycle according to item (1).